/**
 * @license Highcharts JS v5.0.6 (2016-12-07)
 * Accessibility module
 *
 * (c) 2010-2016 Highsoft AS
 * Author: Oystein Moseng
 *
 * License: www.highcharts.com/license
 */
(function (factory) {
  if (typeof module === 'object' && module.exports) {
    module.exports = factory;
  } else {
    factory(Highcharts);
  }
}(function (Highcharts) {
  (function (H) {
    /**
     * Accessibility module
     *
     * (c) 2010-2016 Highsoft AS
     * Author: Oystein Moseng
     *
     * License: www.highcharts.com/license
     */
    'use strict';

    var win = H.win,
      doc = win.document,
      each = H.each,
      erase = H.erase,
      addEvent = H.addEvent,
      removeEvent = H.removeEvent,
      fireEvent = H.fireEvent,
      dateFormat = H.dateFormat,
      merge = H.merge,
      // Human readable description of series and each point in singular and plural
      typeToSeriesMap = {
        'default': ['series', 'data point', 'data points'],
        'line': ['line', 'data point', 'data points'],
        'spline': ['line', 'data point', 'data points'],
        'area': ['line', 'data point', 'data points'],
        'areaspline': ['line', 'data point', 'data points'],
        'pie': ['pie', 'slice', 'slices'],
        'column': ['column series', 'column', 'columns'],
        'bar': ['bar series', 'bar', 'bars'],
        'scatter': ['scatter series', 'data point', 'data points'],
        'boxplot': ['boxplot series', 'box', 'boxes'],
        'arearange': ['arearange series', 'data point', 'data points'],
        'areasplinerange': ['areasplinerange series', 'data point', 'data points'],
        'bubble': ['bubble series', 'bubble', 'bubbles'],
        'columnrange': ['columnrange series', 'column', 'columns'],
        'errorbar': ['errorbar series', 'errorbar', 'errorbars'],
        'funnel': ['funnel', 'data point', 'data points'],
        'pyramid': ['pyramid', 'data point', 'data points'],
        'waterfall': ['waterfall series', 'column', 'columns'],
        'map': ['map', 'area', 'areas'],
        'mapline': ['line', 'data point', 'data points'],
        'mappoint': ['point series', 'data point', 'data points'],
        'mapbubble': ['bubble series', 'bubble', 'bubbles']
      },
      // Descriptions for exotic chart types
      typeDescriptionMap = {
        boxplot: ' Box plot charts are typically used to display groups of statistical data. ' +
        'Each data point in the chart can have up to 5 values: minimum, lower quartile, median, upper quartile and maximum. ',
        arearange: ' Arearange charts are line charts displaying a range between a lower and higher value for each point. ',
        areasplinerange: ' These charts are line charts displaying a range between a lower and higher value for each point. ',
        bubble: ' Bubble charts are scatter charts where each data point also has a size value. ',
        columnrange: ' Columnrange charts are column charts displaying a range between a lower and higher value for each point. ',
        errorbar: ' Errorbar series are used to display the variability of the data. ',
        funnel: ' Funnel charts are used to display reduction of data in stages. ',
        pyramid: ' Pyramid charts consist of a single pyramid with item heights corresponding to each point value. ',
        waterfall: ' A waterfall chart is a column chart where each column contributes towards a total end value. '
      },
      commonKeys = ['name', 'id', 'category', 'x', 'value', 'y'],
      specialKeys = ['z', 'open', 'high', 'q3', 'median', 'q1', 'low', 'close']; // Tell user about all properties if points have one of these defined

    // Default a11y options
    H.setOptions({
      accessibility: {
        enabled: true,
        pointDescriptionThreshold: 30, // set to false to disable
        keyboardNavigation: {
          enabled: true
          //	skipNullPoints: false
        }
        // describeSingleSeries: false
      }
    });

    // Utility function. Reverses child nodes of a DOM element
    function reverseChildNodes(node) {
      var i = node.childNodes.length;
      while (i--) {
        node.appendChild(node.childNodes[i]);
      }
    }

    // Utility function to attempt to fake a click event on an element
    function fakeClickEvent(element) {
      var fakeEvent;
      if (element && element.onclick) {
        fakeEvent = doc.createEvent('Events');
        fakeEvent.initEvent('click', true, false);
        element.onclick(fakeEvent);
      }
    }

    // Whenever drawing series, put info on DOM elements
    H.wrap(H.Series.prototype, 'render', function (proceed) {
      proceed.apply(this, Array.prototype.slice.call(arguments, 1));
      if (this.chart.options.accessibility.enabled) {
        this.setA11yDescription();
      }
    });

    // Put accessible info on series and points of a series
    H.Series.prototype.setA11yDescription = function () {
      var a11yOptions = this.chart.options.accessibility,
        firstPointEl = this.points && this.points.length && this.points[0].graphic && this.points[0].graphic.element,
        seriesEl = firstPointEl && firstPointEl.parentNode || this.graph && this.graph.element || this.group && this.group.element; // Could be tracker series depending on series type

      if (seriesEl) {
        // For some series types the order of elements do not match the order of points in series
        // In that case we have to reverse them in order for AT to read them out in an understandable order
        if (seriesEl.lastChild === firstPointEl) {
          reverseChildNodes(seriesEl);
        }
        // Make individual point elements accessible if possible. Note: If markers are disabled there might not be any elements there to make accessible.
        if (this.points && (this.points.length < a11yOptions.pointDescriptionThreshold || a11yOptions.pointDescriptionThreshold === false)) {
          each(this.points, function (point) {
            if (point.graphic) {
              point.graphic.element.setAttribute('role', 'img');
              point.graphic.element.setAttribute('tabindex', '-1');
              point.graphic.element.setAttribute('aria-label', a11yOptions.pointDescriptionFormatter && a11yOptions.pointDescriptionFormatter(point) ||
                point.buildPointInfoString());
            }
          });
        }
        // Make series element accessible
        if (this.chart.series.length > 1 || a11yOptions.describeSingleSeries) {
          seriesEl.setAttribute('role', 'region');
          seriesEl.setAttribute('tabindex', '-1');
          seriesEl.setAttribute('aria-label', a11yOptions.seriesDescriptionFormatter && a11yOptions.seriesDescriptionFormatter(this) ||
            this.buildSeriesInfoString());
        }
      }
    };

    // Return string with information about series
    H.Series.prototype.buildSeriesInfoString = function () {
      var typeInfo = typeToSeriesMap[this.type] || typeToSeriesMap.default,
        description = this.description || this.options.description;
      return (this.name ? this.name + ', ' : '') +
        (this.chart.types.length === 1 ? typeInfo[0] : 'series') + ' ' + (this.index + 1) + ' of ' + (this.chart.series.length) +
        (this.chart.types.length === 1 ? ' with ' : '. ' + typeInfo[0] + ' with ') +
        (this.points.length + ' ' + (this.points.length === 1 ? typeInfo[1] : typeInfo[2])) +
        (description ? '. ' + description : '') +
        (this.chart.yAxis.length > 1 && this.yAxis ? '. Y axis, ' + this.yAxis.getDescription() : '') +
        (this.chart.xAxis.length > 1 && this.xAxis ? '. X axis, ' + this.xAxis.getDescription() : '');
    };

    // Return string with information about point
    H.Point.prototype.buildPointInfoString = function () {
      var point = this,
        series = point.series,
        a11yOptions = series.chart.options.accessibility,
        infoString = '',
        hasSpecialKey = false,
        dateTimePoint = series.xAxis && series.xAxis.isDatetimeAxis,
        timeDesc = dateTimePoint && dateFormat(a11yOptions.pointDateFormatter && a11yOptions.pointDateFormatter(point) || a11yOptions.pointDateFormat ||
            H.Tooltip.prototype.getXDateFormat(point, series.chart.options.tooltip, series.xAxis), point.x);

      each(specialKeys, function (key) {
        if (point[key] !== undefined) {
          hasSpecialKey = true;
        }
      });

      // If the point has one of the less common properties defined, display all that are defined
      if (hasSpecialKey) {
        if (dateTimePoint) {
          infoString = timeDesc;
        }
        each(commonKeys.concat(specialKeys), function (key) {
          if (point[key] !== undefined && !(dateTimePoint && key === 'x')) {
            infoString += (infoString ? '. ' : '') + key + ', ' + this[key];
          }
        });
      } else {
        // Pick and choose properties for a succint label
        infoString = (this.name || timeDesc || this.category || this.id || 'x, ' + this.x) + ', ' +
          (this.value !== undefined ? this.value : this.y);
      }

      return (this.index + 1) + '. ' + infoString + '.' + (this.description ? ' ' + this.description : '');
    };

    // Get descriptive label for axis
    H.Axis.prototype.getDescription = function () {
      return this.userOptions && this.userOptions.description || this.axisTitle && this.axisTitle.textStr ||
        this.options.id || this.categories && 'categories' || 'values';
    };

    // Pan along axis in a direction (1 or -1), optionally with a defined granularity (number of steps it takes to walk across current view)
    H.Axis.prototype.panStep = function (direction, granularity) {
      var gran = granularity || 3,
        extremes = this.getExtremes(),
        step = (extremes.max - extremes.min) / gran * direction,
        newMax = extremes.max + step,
        newMin = extremes.min + step,
        size = newMax - newMin;
      if (direction < 0 && newMin < extremes.dataMin) {
        newMin = extremes.dataMin;
        newMax = newMin + size;
      } else if (direction > 0 && newMax > extremes.dataMax) {
        newMax = extremes.dataMax;
        newMin = newMax - size;
      }
      this.setExtremes(newMin, newMax);
    };

    // Whenever adding or removing series, keep track of types present in chart
    H.wrap(H.Series.prototype, 'init', function (proceed) {
      proceed.apply(this, Array.prototype.slice.call(arguments, 1));
      var chart = this.chart;
      if (chart.options.accessibility.enabled) {
        chart.types = chart.types || [];

        // Add type to list if does not exist
        if (chart.types.indexOf(this.type) < 0) {
          chart.types.push(this.type);
        }

        addEvent(this, 'remove', function () {
          var removedSeries = this,
            hasType = false;

          // Check if any of the other series have the same type as this one. Otherwise remove it from the list.
          each(chart.series, function (s) {
            if (s !== removedSeries && chart.types.indexOf(removedSeries.type) < 0) {
              hasType = true;
            }
          });
          if (!hasType) {
            erase(chart.types, removedSeries.type);
          }
        });
      }
    });

    // Return simplified description of chart type. Some types will not be familiar to most screen reader users, but we try.
    H.Chart.prototype.getTypeDescription = function () {
      var firstType = this.types && this.types[0],
        mapTitle = this.series[0] && this.series[0].mapTitle;
      if (!firstType) {
        return 'Empty chart.';
      } else if (firstType === 'map') {
        return mapTitle ? 'Map of ' + mapTitle : 'Map of unspecified region.';
      } else if (this.types.length > 1) {
        return 'Combination chart.';
      } else if (['spline', 'area', 'areaspline'].indexOf(firstType) > -1) {
        return 'Line chart.';
      }
      return firstType + ' chart.' + (typeDescriptionMap[firstType] || '');
    };

    // Return object with text description of each of the chart's axes
    H.Chart.prototype.getAxesDescription = function () {
      var numXAxes = this.xAxis.length,
        numYAxes = this.yAxis.length,
        desc = {},
        i;

      if (numXAxes) {
        desc.xAxis = 'The chart has ' + numXAxes + (numXAxes > 1 ? ' X axes' : ' X axis') + ' displaying ';
        if (numXAxes < 2) {
          desc.xAxis += this.xAxis[0].getDescription() + '.';
        } else {
          for (i = 0; i < numXAxes - 1; ++i) {
            desc.xAxis += (i ? ', ' : '') + this.xAxis[i].getDescription();
          }
          desc.xAxis += ' and ' + this.xAxis[i].getDescription() + '.';
        }
      }

      if (numYAxes) {
        desc.yAxis = 'The chart has ' + numYAxes + (numYAxes > 1 ? ' Y axes' : ' Y axis') + ' displaying ';
        if (numYAxes < 2) {
          desc.yAxis += this.yAxis[0].getDescription() + '.';
        } else {
          for (i = 0; i < numYAxes - 1; ++i) {
            desc.yAxis += (i ? ', ' : '') + this.yAxis[i].getDescription();
          }
          desc.yAxis += ' and ' + this.yAxis[i].getDescription() + '.';
        }
      }

      return desc;
    };

    // Set a11y attribs on exporting menu
    H.Chart.prototype.addAccessibleContextMenuAttribs = function () {
      var exportList = this.exportDivElements;
      if (exportList) {
        // Set tabindex on the menu items to allow focusing by script
        // Set role to give screen readers a chance to pick up the contents
        each(exportList, function (item) {
          if (item.tagName === 'DIV' && !(item.children && item.children.length)) {
            item.setAttribute('role', 'menuitem');
            item.setAttribute('tabindex', -1);
          }
        });
        // Set accessibility properties on parent div
        exportList[0].parentNode.setAttribute('role', 'menu');
        exportList[0].parentNode.setAttribute('aria-label', 'Chart export');
      }
    };

    // Highlight a point (show tooltip and display hover state). Returns the highlighted point.
    H.Point.prototype.highlight = function () {
      var chart = this.series.chart;
      if (this.graphic && this.graphic.element.focus) {
        this.graphic.element.focus();
      }
      if (!this.isNull) {
        this.onMouseOver(); // Show the hover marker
        chart.tooltip.refresh(chart.tooltip.shared ? [this] : this); // Show the tooltip
      } else {
        chart.tooltip.hide(0);
        // Don't call blur on the element, as it messes up the chart div's focus
      }
      chart.highlightedPoint = this;
      return this;
    };

    // Function to highlight next/previous point in chart
    // Returns highlighted point on success, false on failure (no adjacent point to highlight in chosen direction)
    H.Chart.prototype.highlightAdjacentPoint = function (next) {
      var series = this.series,
        curPoint = this.highlightedPoint,
        curPointIndex = curPoint && curPoint.index || 0,
        newSeries,
        newPoint;

      // If no points, return false
      if (!series[0] || !series[0].points) {
        return false;
      }

      // Use first point if none already highlighted
      if (!curPoint) {
        return series[0].points[0].highlight();
      }

      // Find index of current point in series.points array. Necessary for dataGrouping (and maybe zoom?)
      if (curPoint.series.points[curPointIndex] !== curPoint) {
        for (var i = 0; i < curPoint.series.points.length; ++i) {
          if (curPoint.series.points[i] === curPoint) {
            curPointIndex = i;
            break;
          }
        }
      }

      // Try to grab next/prev point
      newSeries = series[curPoint.series.index + (next ? 1 : -1)];
      newPoint = curPoint.series.points[curPointIndex + (next ? 1 : -1)] || newSeries && newSeries.points[next ? 0 : newSeries.points.length - 1];

      // If there is no adjacent point, we return false
      if (newPoint === undefined) {
        return false;
      }

      // Recursively skip null points
      if (newPoint.isNull && this.options.accessibility.keyboardNavigation &&
        this.options.accessibility.keyboardNavigation.skipNullPoints) {
        this.highlightedPoint = newPoint;
        return this.highlightAdjacentPoint(next);
      }

      // There is an adjacent point, highlight it
      return newPoint.highlight();
    };

    // Show the export menu and focus the first item (if exists)
    H.Chart.prototype.showExportMenu = function () {
      if (this.exportSVGElements && this.exportSVGElements[0]) {
        this.exportSVGElements[0].element.onclick();
        this.highlightExportItem(0);
      }
    };

    // Highlight export menu item by index
    H.Chart.prototype.highlightExportItem = function (ix) {
      var listItem = this.exportDivElements && this.exportDivElements[ix],
        curHighlighted = this.exportDivElements && this.exportDivElements[this.highlightedExportItem];

      if (listItem && listItem.tagName === 'DIV' && !(listItem.children && listItem.children.length)) {
        if (listItem.focus) {
          listItem.focus();
        }
        if (curHighlighted && curHighlighted.onmouseout) {
          curHighlighted.onmouseout();
        }
        if (listItem.onmouseover) {
          listItem.onmouseover();
        }
        this.highlightedExportItem = ix;
        return true;
      }
    };

    // Highlight range selector button by index
    H.Chart.prototype.highlightRangeSelectorButton = function (ix) {
      var buttons = this.rangeSelector.buttons;
      // Deselect old
      if (buttons[this.highlightedRangeSelectorItemIx]) {
        buttons[this.highlightedRangeSelectorItemIx].setState(this.oldRangeSelectorItemState || 0);
      }
      // Select new
      this.highlightedRangeSelectorItemIx = ix;
      if (buttons[ix]) {
        if (buttons[ix].element.focus) {
          buttons[ix].element.focus();
        }
        this.oldRangeSelectorItemState = buttons[ix].state;
        buttons[ix].setState(2);
        return true;
      }
      return false;
    };

    // Highlight legend item by index
    H.Chart.prototype.highlightLegendItem = function (ix) {
      var items = this.legend.allItems;
      if (items[this.highlightedLegendItemIx]) {
        fireEvent(items[this.highlightedLegendItemIx].legendGroup.element, 'mouseout');
      }
      this.highlightedLegendItemIx = ix;
      if (items[ix]) {
        if (items[ix].legendGroup.element.focus) {
          items[ix].legendGroup.element.focus();
        }
        fireEvent(items[ix].legendGroup.element, 'mouseover');
        return true;
      }
      return false;
    };

    // Hide export menu
    H.Chart.prototype.hideExportMenu = function () {
      var exportList = this.exportDivElements;
      if (exportList) {
        each(exportList, function (el) {
          fireEvent(el, 'mouseleave');
        });
        if (exportList[this.highlightedExportItem] && exportList[this.highlightedExportItem].onmouseout) {
          exportList[this.highlightedExportItem].onmouseout();
        }
        this.highlightedExportItem = 0;
        this.renderTo.focus();
      }
    };

    // Add keyboard navigation handling to chart
    H.Chart.prototype.addKeyboardNavEvents = function () {
      var chart = this;

      // Abstraction layer for keyboard navigation. Keep a map of keyCodes to handler functions, and a next/prev move handler for tab order.
      // The module's keyCode handlers determine when to move to another module.
      // Validate holds a function to determine if there are prerequisites for this module to run that are not met.
      // Init holds a function to run once before any keyCodes are interpreted.
      // transformTabs determines whether to transform tabs to left/right events or not. Defaults to true.
      function KeyboardNavigationModule(options) {
        this.keyCodeMap = options.keyCodeMap;
        this.move = options.move;
        this.validate = options.validate;
        this.init = options.init;
        this.transformTabs = options.transformTabs !== false;
      }

      KeyboardNavigationModule.prototype = {
        // Find handler function(s) for key code in the keyCodeMap and run it.
        run: function (e) {
          var navModule = this,
            keyCode = e.which || e.keyCode,
            handled = false;
          keyCode = this.transformTabs && keyCode === 9 ? (e.shiftKey ? 37 : 39) : keyCode; // Transform tabs
          each(this.keyCodeMap, function (codeSet) {
            if (codeSet[0].indexOf(keyCode) > -1) {
              handled = codeSet[1].call(navModule, keyCode, e) === false ? false : true; // If explicitly returning false, we haven't handled it
            }
          });
          return handled;
        }
      };
      // Maintain abstraction between KeyboardNavigationModule and Highcharts
      // The chart object keeps track of a list of KeyboardNavigationModules that we move through
      function navModuleFactory(keyMap, options) {
        return new KeyboardNavigationModule(merge({
          keyCodeMap: keyMap,
          // Move to next/prev valid module, or undefined if none, and init it.
          // Returns true on success and false if there is no valid module to move to.
          move: function (direction) {
            chart.keyboardNavigationModuleIndex += direction;
            var newModule = chart.keyboardNavigationModules[chart.keyboardNavigationModuleIndex];
            if (newModule) {
              if (newModule.validate && !newModule.validate()) {
                return this.move(direction); // Invalid module
              }
              if (newModule.init) {
                newModule.init(direction); // Valid module, init it
                return true;
              }
            }
            // No module
            chart.keyboardNavigationModuleIndex = 0; // Reset counter
            chart.slipNextTab = true; // Allow next tab to slip, as we will have focus on chart now
            return false;
          }
        }, options));
      }

      // Route keydown events
      function keydownHandler(ev) {
        var e = ev || win.event,
          keyCode = e.which || e.keyCode,
          curNavModule = chart.keyboardNavigationModules[chart.keyboardNavigationModuleIndex];

        // Handle tabbing
        if (keyCode === 9) {
          // If we reached end of chart, we need to let this tab slip through to allow users to tab further
          if (chart.slipNextTab) {
            chart.slipNextTab = false;
            return;
          }
        }
        // If key was not tab, don't slip the next tab
        chart.slipNextTab = false;

        // If there is a navigation module for the current index, run it. Otherwise, we are outside of the chart in some direction.
        if (curNavModule) {
          if (curNavModule.run(e)) {
            e.preventDefault(); // If successfully handled, stop the event here.
          }
        }
      }

      // List of the different keyboard handling modes we use depending on where we are in the chart.
      // Each mode has a set of handling functions mapped to key codes.
      // Each mode determines when to move to the next/prev mode.
      chart.keyboardNavigationModules = [
        // Points
        navModuleFactory([
          // Left/Right
          [
            [37, 39],
            function (keyCode) {
              if (!chart.highlightAdjacentPoint(keyCode === 39)) { // Try to highlight adjacent point
                return this.move(keyCode === 39 ? 1 : -1); // Failed. Move to next/prev module
              }
            }
          ],
          // Up/Down
          [
            [38, 40],
            function (keyCode) {
              var newSeries;
              if (chart.highlightedPoint) {
                newSeries = chart.series[chart.highlightedPoint.series.index + (keyCode === 38 ? -1 : 1)]; // Find prev/next series
                if (newSeries && newSeries.points[0]) { // If series exists and has data, go for it
                  newSeries.points[0].highlight();
                } else {
                  return this.move(keyCode === 40 ? 1 : -1); // Otherwise, attempt to move to next/prev module
                }
              }
            }
          ],
          // Enter/Spacebar
          [
            [13, 32],
            function () {
              if (chart.highlightedPoint) {
                chart.highlightedPoint.firePointEvent('click');
              }
            }
          ]
        ], {
          // If coming back to points from other module, highlight last point
          init: function (direction) {
            var lastSeries = chart.series && chart.series[chart.series.length - 1],
              lastPoint = lastSeries && lastSeries.points && lastSeries.points[lastSeries.points.length - 1];
            if (direction < 0 && lastPoint) {
              lastPoint.highlight();
            }
          }
        }),

        // Exporting
        navModuleFactory([
          // Left/Up
          [
            [37, 38],
            function () {
              var i = chart.highlightedExportItem || 0,
                reachedEnd = true,
                series = chart.series,
                newSeries;
              // Try to highlight prev item in list. Highlighting e.g. separators will fail.
              while (i--) {
                if (chart.highlightExportItem(i)) {
                  reachedEnd = false;
                  break;
                }
              }
              if (reachedEnd) {
                chart.hideExportMenu();
                // Wrap to last point
                if (series && series.length) {
                  newSeries = series[series.length - 1];
                  if (newSeries.points.length) {
                    newSeries.points[newSeries.points.length - 1].highlight();
                  }
                }
                // Try to move to prev module (should be points, since we wrapped to last point)
                return this.move(-1);
              }
            }
          ],
          // Right/Down
          [
            [39, 40],
            function () {
              var highlightedExportItem = chart.highlightedExportItem || 0,
                reachedEnd = true;
              // Try to highlight next item in list. Highlighting e.g. separators will fail.
              for (var i = highlightedExportItem + 1; i < chart.exportDivElements.length; ++i) {
                if (chart.highlightExportItem(i)) {
                  reachedEnd = false;
                  break;
                }
              }
              if (reachedEnd) {
                chart.hideExportMenu();
                return this.move(1); // Next module
              }
            }
          ],
          // Enter/Spacebar
          [
            [13, 32],
            function () {
              fakeClickEvent(chart.exportDivElements[chart.highlightedExportItem]);
            }
          ]
        ], {
          // Only run exporting navigation if exporting support exists and is enabled on chart
          validate: function () {
            return chart.exportChart && !(chart.options.exporting && chart.options.exporting.enabled === false);
          },
          // Show export menu
          init: function (direction) {
            chart.highlightedPoint = null;
            chart.showExportMenu();
            // If coming back to export menu from other module, try to highlight last item in menu
            if (direction < 0 && chart.exportDivElements) {
              for (var i = chart.exportDivElements.length; i > -1; --i) {
                if (chart.highlightExportItem(i)) {
                  break;
                }
              }
            }
          }
        }),

        // Map zoom
        navModuleFactory([
          // Up/down/left/right
          [
            [38, 40, 37, 39],
            function (keyCode) {
              chart[keyCode === 38 || keyCode === 40 ? 'yAxis' : 'xAxis'][0].panStep(keyCode < 39 ? -1 : 1);
            }
          ],

          // Tabs
          [
            [9],
            function (keyCode, e) {
              var button;
              chart.mapNavButtons[chart.focusedMapNavButtonIx].setState(0); // Deselect old
              if (e.shiftKey && !chart.focusedMapNavButtonIx || !e.shiftKey && chart.focusedMapNavButtonIx) { // trying to go somewhere we can't?
                chart.mapZoom(); // Reset zoom
                return this.move(e.shiftKey ? -1 : 1); // Nowhere to go, go to prev/next module
              }
              chart.focusedMapNavButtonIx += e.shiftKey ? -1 : 1;
              button = chart.mapNavButtons[chart.focusedMapNavButtonIx];
              if (button.element.focus) {
                button.element.focus();
              }
              button.setState(2);
            }
          ],

          // Enter/Spacebar
          [
            [13, 32],
            function () {
              fakeClickEvent(chart.mapNavButtons[chart.focusedMapNavButtonIx].element);
            }
          ]
        ], {
          // Only run this module if we have map zoom on the chart
          validate: function () {
            return chart.mapZoom && chart.mapNavButtons && chart.mapNavButtons.length === 2;
          },

          // Handle tabs separately
          transformTabs: false,

          // Make zoom buttons do their magic
          init: function (direction) {
            var zoomIn = chart.mapNavButtons[0],
              zoomOut = chart.mapNavButtons[1],
              initialButton = direction > 0 ? zoomIn : zoomOut;

            each(chart.mapNavButtons, function (button, i) {
              button.element.setAttribute('tabindex', -1);
              button.element.setAttribute('role', 'button');
              button.element.setAttribute('aria-label', 'Zoom ' + (i ? 'out' : '') + 'chart');
            });

            if (initialButton.element.focus) {
              initialButton.element.focus();
            }
            initialButton.setState(2);
            chart.focusedMapNavButtonIx = direction > 0 ? 0 : 1;
          }
        }),

        // Highstock range selector (minus input boxes)
        navModuleFactory([
          // Left/Right/Up/Down
          [
            [37, 39, 38, 40],
            function (keyCode) {
              var direction = (keyCode === 37 || keyCode === 38) ? -1 : 1;
              // Try to highlight next/prev button
              if (!chart.highlightRangeSelectorButton(chart.highlightedRangeSelectorItemIx + direction)) {
                return this.move(direction);
              }
            }
          ],
          // Enter/Spacebar
          [
            [13, 32],
            function () {
              if (chart.oldRangeSelectorItemState !== 3) { // Don't allow click if button used to be disabled
                fakeClickEvent(chart.rangeSelector.buttons[chart.highlightedRangeSelectorItemIx].element);
              }
            }
          ]
        ], {
          // Only run this module if we have range selector
          validate: function () {
            return chart.rangeSelector && chart.rangeSelector.buttons && chart.rangeSelector.buttons.length;
          },

          // Make elements focusable and accessible
          init: function (direction) {
            each(chart.rangeSelector.buttons, function (button) {
              button.element.setAttribute('tabindex', '-1');
              button.element.setAttribute('role', 'button');
              button.element.setAttribute('aria-label', 'Select range ' + (button.text && button.text.textStr));
            });
            // Focus first/last button
            chart.highlightRangeSelectorButton(direction > 0 ? 0 : chart.rangeSelector.buttons.length - 1);
          }
        }),

        // Highstock range selector, input boxes
        navModuleFactory([
          // Tab/Up/Down
          [
            [9, 38, 40],
            function (keyCode, e) {
              var direction = (keyCode === 9 && e.shiftKey || keyCode === 38) ? -1 : 1,
                newIx = chart.highlightedInputRangeIx = chart.highlightedInputRangeIx + direction;
              // Try to highlight next/prev item in list.
              if (newIx > 1 || newIx < 0) { // Out of range
                return this.move(direction);
              }
              chart.rangeSelector[newIx ? 'maxInput' : 'minInput'].focus(); // Input boxes are HTML, and should have focus support in all browsers
            }
          ]
        ], {
          // Only run if we have range selector with input boxes
          validate: function () {
            var inputVisible = chart.rangeSelector && chart.rangeSelector.inputGroup && chart.rangeSelector.inputGroup.element.getAttribute('visibility') !== 'hidden';
            return inputVisible && chart.options.rangeSelector.inputEnabled !== false && chart.rangeSelector.minInput && chart.rangeSelector.maxInput;
          },

          // Handle tabs different from left/right (because we don't want to catch left/right in a text area)
          transformTabs: false,

          // Highlight first/last input box
          init: function (direction) {
            chart.highlightedInputRangeIx = direction > 0 ? 0 : 1;
            chart.rangeSelector[chart.highlightedInputRangeIx ? 'maxInput' : 'minInput'].focus();
          }
        }),

        // Legend navigation
        navModuleFactory([
          // Left/Right/Up/Down
          [
            [37, 39, 38, 40],
            function (keyCode) {
              var direction = (keyCode === 37 || keyCode === 38) ? -1 : 1;
              // Try to highlight next/prev legend item
              if (!chart.highlightLegendItem(chart.highlightedLegendItemIx + direction)) {
                return this.move(direction);
              }
            }
          ],
          // Enter/Spacebar
          [
            [13, 32],
            function () {
              fakeClickEvent(chart.legend.allItems[chart.highlightedLegendItemIx].legendItem.element.parentNode);
            }
          ]
        ], {
          // Only run this module if we have at least one legend - wait for it - item.
          validate: function () {
            return chart.legend && chart.legend.allItems && !chart.colorAxis;
          },

          // Make elements focusable and accessible
          init: function (direction) {
            each(chart.legend.allItems, function (item) {
              item.legendGroup.element.setAttribute('tabindex', '-1');
              item.legendGroup.element.setAttribute('role', 'button');
              item.legendGroup.element.setAttribute('aria-label', 'Toggle visibility of series ' + item.name);
            });
            // Focus first/last item
            chart.highlightLegendItem(direction > 0 ? 0 : chart.legend.allItems.length - 1);
          }
        })
      ];

      // Init nav module index. We start at the first module, and as the user navigates through the chart the index will increase to use different handler modules.
      chart.keyboardNavigationModuleIndex = 0;

      // Make chart reachable by tab
      if (!chart.renderTo.tabIndex) {
        chart.renderTo.setAttribute('tabindex', '0');
      }

      // Handle keyboard events
      addEvent(chart.renderTo, 'keydown', keydownHandler);
      addEvent(chart, 'destroy', function () {
        removeEvent(chart.renderTo, 'keydown', keydownHandler);
      });
    };

    // Add screen reader region to chart.
    // tableId is the HTML id of the table to focus when clicking the table anchor in the screen reader region.
    H.Chart.prototype.addScreenReaderRegion = function (tableId) {
      var chart = this,
        series = chart.series,
        options = chart.options,
        a11yOptions = options.accessibility,
        hiddenSection = chart.screenReaderRegion = doc.createElement('div'),
        tableShortcut = doc.createElement('h3'),
        tableShortcutAnchor = doc.createElement('a'),
        chartHeading = doc.createElement('h3'),
        hiddenStyle = { // CSS style to hide element from visual users while still exposing it to screen readers
          position: 'absolute',
          left: '-9999px',
          top: 'auto',
          width: '1px',
          height: '1px',
          overflow: 'hidden'
        },
        chartTypes = chart.types || [],
        // Build axis info - but not for pies and maps. Consider not adding for certain other types as well (funnel, pyramid?)
        axesDesc = (chartTypes.length === 1 && chartTypes[0] === 'pie' || chartTypes[0] === 'map') && {} || chart.getAxesDescription(),
        chartTypeInfo = series[0] && typeToSeriesMap[series[0].type] || typeToSeriesMap.default;

      hiddenSection.setAttribute('role', 'region');
      hiddenSection.setAttribute('aria-label', 'Chart screen reader information.');

      hiddenSection.innerHTML = a11yOptions.screenReaderSectionFormatter && a11yOptions.screenReaderSectionFormatter(chart) ||
        '<div tabindex="0">Use regions/landmarks to skip ahead to chart' +
        (series.length > 1 ? ' and navigate between data series' : '') + '.</div><h3>Summary.</h3><div>' + (options.title.text || 'Chart') +
        (options.subtitle && options.subtitle.text ? '. ' + options.subtitle.text : '') +
        '</div><h3>Long description.</h3><div>' + (options.chart.description || 'No description available.') +
        '</div><h3>Structure.</h3><div>Chart type: ' + (options.chart.typeDescription || chart.getTypeDescription()) + '</div>' +
        (series.length === 1 ? '<div>' + chartTypeInfo[0] + ' with ' + series[0].points.length + ' ' +
        (series[0].points.length === 1 ? chartTypeInfo[1] : chartTypeInfo[2]) + '.</div>' : '') +
        (axesDesc.xAxis ? ('<div>' + axesDesc.xAxis + '</div>') : '') +
        (axesDesc.yAxis ? ('<div>' + axesDesc.yAxis + '</div>') : '');

      // Add shortcut to data table if export-csv is loaded
      if (chart.getCSV) {
        tableShortcutAnchor.innerHTML = 'View as data table.';
        tableShortcutAnchor.href = '#' + tableId;
        tableShortcutAnchor.setAttribute('tabindex', '-1'); // Make this unreachable by user tabbing
        tableShortcutAnchor.onclick = a11yOptions.onTableAnchorClick || function () {
            chart.viewData();
            doc.getElementById(tableId).focus();
          };
        tableShortcut.appendChild(tableShortcutAnchor);

        hiddenSection.appendChild(tableShortcut);
      }

      chartHeading.innerHTML = 'Chart graphic.';
      chart.renderTo.insertBefore(chartHeading, chart.renderTo.firstChild);
      chart.renderTo.insertBefore(hiddenSection, chart.renderTo.firstChild);

      // Hide the section and the chart heading
      merge(true, chartHeading.style, hiddenStyle);
      merge(true, hiddenSection.style, hiddenStyle);
    };


    // Make chart container accessible, and wrap table functionality
    H.Chart.prototype.callbacks.push(function (chart) {
      var options = chart.options,
        a11yOptions = options.accessibility;

      if (!a11yOptions.enabled) {
        return;
      }

      var titleElement = doc.createElementNS('http://www.w3.org/2000/svg', 'title'),
        exportGroupElement = doc.createElementNS('http://www.w3.org/2000/svg', 'g'),
        descElement = chart.container.getElementsByTagName('desc')[0],
        textElements = chart.container.getElementsByTagName('text'),
        titleId = 'highcharts-title-' + chart.index,
        tableId = 'highcharts-data-table-' + chart.index,
        chartTitle = options.title.text || 'Chart',
        oldColumnHeaderFormatter = options.exporting && options.exporting.csv && options.exporting.csv.columnHeaderFormatter,
        topLevelColumns = [];

      // Add SVG title/desc tags
      titleElement.textContent = chartTitle;
      titleElement.id = titleId;
      descElement.parentNode.insertBefore(titleElement, descElement);
      chart.renderTo.setAttribute('role', 'region');
      chart.renderTo.setAttribute('aria-label', chartTitle + '. Use up and down arrows to navigate.');

      // Set screen reader properties on export menu
      if (chart.exportSVGElements && chart.exportSVGElements[0] && chart.exportSVGElements[0].element) {
        var oldExportCallback = chart.exportSVGElements[0].element.onclick,
          parent = chart.exportSVGElements[0].element.parentNode;
        chart.exportSVGElements[0].element.onclick = function () {
          oldExportCallback.apply(this, Array.prototype.slice.call(arguments));
          chart.addAccessibleContextMenuAttribs();
          chart.highlightExportItem(0);
        };
        chart.exportSVGElements[0].element.setAttribute('role', 'button');
        chart.exportSVGElements[0].element.setAttribute('aria-label', 'View export menu');
        exportGroupElement.appendChild(chart.exportSVGElements[0].element);
        exportGroupElement.setAttribute('role', 'region');
        exportGroupElement.setAttribute('aria-label', 'Chart export menu');
        parent.appendChild(exportGroupElement);
      }

      // Set screen reader properties on input boxes for range selector. We need to do this regardless of whether or not these are visible, as they are 
      // by default part of the page's tabindex unless we set them to -1.
      if (chart.rangeSelector) {
        each(['minInput', 'maxInput'], function (key, i) {
          if (chart.rangeSelector[key]) {
            chart.rangeSelector[key].setAttribute('tabindex', '-1');
            chart.rangeSelector[key].setAttribute('role', 'textbox');
            chart.rangeSelector[key].setAttribute('aria-label', 'Select ' + (i ? 'end' : 'start') + ' date.');
          }
        });
      }

      // Hide text elements from screen readers
      each(textElements, function (el) {
        el.setAttribute('aria-hidden', 'true');
      });

      // Add top-secret screen reader region
      chart.addScreenReaderRegion(tableId);

      // Enable keyboard navigation
      if (a11yOptions.keyboardNavigation) {
        chart.addKeyboardNavEvents();
      }

      /* Wrap table functionality from export-csv */

      // Keep track of columns
      merge(true, options.exporting, {
        csv: {
          columnHeaderFormatter: function (series, key, keyLength) {
            var prevCol = topLevelColumns[topLevelColumns.length - 1];
            if (keyLength > 1) {
              // We need multiple levels of column headers
              // Populate a list of column headers to add in addition to the ones added by export-csv
              if ((prevCol && prevCol.text) !== series.name) {
                topLevelColumns.push({
                  text: series.name,
                  span: keyLength
                });
              }
            }
            if (oldColumnHeaderFormatter) {
              return oldColumnHeaderFormatter.call(this, series, key, keyLength);
            }
            return keyLength > 1 ? key : series.name;
          }
        }
      });

      // Add ID and title/caption to table HTML
      H.wrap(chart, 'getTable', function (proceed) {
        return proceed.apply(this, Array.prototype.slice.call(arguments, 1))
          .replace('<table>', '<table id="' + tableId + '" summary="Table representation of chart"><caption>' + chartTitle + '</caption>');
      });

      // Add accessibility attributes and top level columns
      H.wrap(chart, 'viewData', function (proceed) {
        if (!this.insertedTable) {
          proceed.apply(this, Array.prototype.slice.call(arguments, 1));

          var table = doc.getElementById(tableId),
            body = table.getElementsByTagName('tbody')[0],
            firstRow = body.firstChild.children,
            columnHeaderRow = '<tr><td></td>',
            cell,
            newCell;

          // Make table focusable by script
          table.setAttribute('tabindex', '-1');

          // Create row headers
          each(body.children, function (el) {
            cell = el.firstChild;
            newCell = doc.createElement('th');
            newCell.setAttribute('scope', 'row');
            newCell.innerHTML = cell.innerHTML;
            cell.parentNode.replaceChild(newCell, cell);
          });

          // Set scope for column headers
          each(firstRow, function (el) {
            if (el.tagName === 'TH') {
              el.setAttribute('scope', 'col');
            }
          });

          // Add top level columns
          if (topLevelColumns.length) {
            each(topLevelColumns, function (col) {
              columnHeaderRow += '<th scope="col" colspan="' + col.span + '">' + col.text + '</th>';
            });
            body.insertAdjacentHTML('afterbegin', columnHeaderRow);
          }
        }
      });
    });

  }(Highcharts));
}));
